3 1 4 Bulletin American Museum of Natural History. [Vol, XVI, 



3. "L." esulcatus Cope. White River (? Titanotheriutn 

 Beds), Swift Current Creek, Canada. 



Cope, Mem. Geol. Sur. Can. Ill, 189 1, 22, pi. xiv fig. 5. 



Based on a single upper molar, which, judging from Cope's 

 figure, is not Leptomeryx, suggesting rather an ally of Pal- 

 cBomeryx, so far as such slight evidence is worth consider- 

 ation. 



4. "L." semicinctus Cope. White River ( ? Titanotherium 

 Beds), Swift Current Creek, Canada. 



Cope, /. c, p. 23, pi. xiv, fig. 8. 



This species is also known by a single upper molar. It has 

 twice the linear dimensions of L. evansi; tooth broader 

 transversely, with heavy cingular ridge (protostyle) internal 

 to protocone and strong cusp (hypostyle) anterointernal to 

 hypocone. This is clearly not Leptomeryx, and is distinct 

 from any described White River genus (except possibly Gal- 

 ops, with which I am unable to compare it; Prof. Marsh 

 states, however, that the molars of Galops are like those 

 of Protoceras, in which case it is not "L." semicinctus). 

 Two upper molars in the Am. Mus. Collection from the 

 Protoceras Beds of South Dakota probably represent this 

 species. 



5. Leptomeryx sp. indesc. 



A smaller species occurs in the Leptauchenia clays in Col- 

 orado and in the Protoceras Beds of South Dakota distin- 

 guished by simpler premolars, narrower, more hypsodont 

 molars. The deuteroconid of p^ is not distinct as in L. 

 evansi, but represented only by a ridge descending ante- 

 rointernally from the point of the protoconid; P3 is smaller 

 and more trenchant; the internal faces of the molar cusps 

 are more convex. This may prove varietal when L. evansi 

 is examined from more localities and regions. 



6. Leptomeryx sp. indesc. 



A larger, somewhat more brachydont species or variety, 

 characteristic of the Protoceras sandstones. Premolars pro- 



